Physical properties of the specific PapG–galabiose binding in E. coli P pili-mediated adhesion
2009 (English)In: European Biophysics Journal, ISSN 0175-7571, E-ISSN 1432-1017, Vol. 38, no 2, 245-254 p.Article in journal (Refereed) Published
Detailed analyses of the mechanisms thatmediate binding of the uropathogenic Escherichia coli tohost cells are essential, as attachment is a prerequisite forthe subsequent infection process. We explore, by means offorce measuring optical tweezers, the interaction betweenthe galabiose receptor and the adhesin PapG expressed byP pili on single bacterial cells. Two variants of dynamicforce spectroscopy were applied based on constant andnon-linear loading force. The specific PapG–galabiosebinding showed typical slip-bond behaviour in the forceinterval (30–100 pN) set by the pilus intrinsic biomechanicalproperties. Moreover, it was found that the bondhas a thermodynamic off-rate and a bond length of2.6×10-3 s-1 and 5.0 Å , respectively. Consequently, thePapG–galabiose complex is significantly stronger thanthe internal bonds in the P pilus structure that stabilizes thehelical chain-like macromolecule. This finding suggeststhat the specific binding is strong enough to enable the Ppili rod to unfold when subjected to strong shear forces inthe urinary tract. The unfolding process of the P pili rodpromotes the formation of strong multipili interaction,which is important for the bacterium to maintain attachmentto the host cells.
Place, publisher, year, edition, pages
New York: Springer , 2009. Vol. 38, no 2, 245-254 p.
Escherichia coli, Non-covalent single bond, Slip-bond, Dynamic force spectroscopy, Receptor–ligand interaction
Cell Biology Biochemistry and Molecular Biology
Research subject Physics
IdentifiersURN: urn:nbn:se:umu:diva-19734DOI: 10.1007/s00249-008-0376-yISI: 000262671600011OAI: oai:DiVA.org:umu-19734DiVA: diva2:202465